Endoscopic bipolar electrocautery instruments

ABSTRACT

An endoscopic bipolar electrocautery instrument includes a proximal actuator coupled by a tube and push rod to a pair of distal graspers. The tube is covered with an insulating shrink wrap from its distal end up to an uncovered proximal portion. A stationary jaw with an integral clevis is mounted inside the distal end of the tube and electrically contacts the inner surface thereof. The clevis holds a pair of ceramic insulators between which a movable jaw is mounted on an insulated bushing with an axle pin. The movable jaw is electrically and mechanically coupled to the push rod which is covered with an insulating shrink wrap from a point just proximal of its connection with the movable jaw to a point near its proximal end. The uninsulated proximal end of the tube is mounted in a conductive bushing which rotates within a nonconductive handle. The proximal end of the push rod extends beyond the conductive bushing and a rubber insulator is fitted between the bushing and the push rod. A nonconductive actuating lever is hingedly attached to the handle and the push rod is rotatingly coupled thereto. A pair of Y-shaped electrical wiper contacts are insert molded in a nonconductive member mounted in the handle and respectively contact the bushing and uninsulated portion of the push rod on either side of the rubber insulator. A bipolar cable insert molded in the nonconductive member is coupled to these contacts and to a source of current.

This application is continuation of U.S. application Ser. No.08/091,177, filed Jul. 13, 1993, now U.S. Pat. No. 5,395,369, which inturn is a continuation-in-part of co-owned, copending Ser. No.08/074,790 filed Jun. 10, 1993 (Endoscopic Instrument Incorporating anElastomeric Fluid Seal), now U.S. Pat. No. 5,395,364 which is herebyincorporated by reference herein. This application also relates toco-owned, Ser. No. 07/959,280 (Endoscopic ElectrosurgicalSuction-Irrigation Instrument), and now U.S. Pat. No. 5,314,406 and Ser.No. 08/016,595 (Endoscopic Biopsy Forceps Devices With Selective BipolarCautery), now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to endoscopic surgical devices. Moreparticularly, this invention relates to an endoscopic surgicalinstrument having bipolar electrocautery grasping end effectors. Thesurgical instrument of the invention has particular application as aprobe which extends through a suction-irrigation cautery instrument asset forth in Ser. No. 07/959,280.

2. State of the Art

Endoscopic surgery is widely practiced throughout the world today andits acceptance is growing rapidly. In general, endoscopic surgeryinvolves one or more incisions made by trocars where trocar tubes areleft in place so that endoscopic surgical instruments may be insertedthrough the tubes. A camera or other optical instrument is ofteninserted through one trocar tube, while a cutter, dissector, or othersurgical instrument is inserted through another trocar tube for purposesof manipulating and/or cutting the internal organ. Sometimes it isdesirable to have several trocar tubes in place at once in order toreceive several surgical instruments. In this manner, organ or tissuemay be grasped with one surgical instrument, and simultaneously may becut with another surgical instrument; all under view of the surgeon.

Various types of endoscopic surgical instruments are known in the art.These instruments generally comprise a slender tube containing a pushrod which is axially movable within the tube by means of a handle ortrigger-like actuating means. An end effector is provided at the distalend of the tube and is coupled to the push rod by means of a clevis sothat axial movement of the push rod is translated to rotational orpivotal movement of the end effector. End effectors may take the form ofscissors, grippers, cutting jaws, forceps, and the like.

Modern endoscopic procedures often involve the use of electrocautery.Indeed, several types of electrocautery devices for use in endoscopicsurgery are described in the prior art. U.S. Pat. No. 4,418,692 to Guay,for example, discloses a device for use in laparoscopic tubalcauterization for blocking the fallopian tubes of a patient. The devicecomprises a substantially tubular body member having a spring-biasedpiston slidably mounted therein. A pair of electrodes (either monopolaror bipolar) are disposed to grasp living tissue when the piston is in afirst position biased by the spring and to release the tissue when abutton is pressed which moves the piston into a second position. Thedevice includes a circuit breaker which interrupts current flowing tothe electrodes when the piston is in the second position. When theelectrodes grasp the tissue, current is supplied to the surface of theelectrode. Guay teaches two types of grasping electrodes: a springytweezer-like electrode pair; and a sliding J-hook type electrode.

Another electrosurgical instrument for use in combination with anendoscope is disclosed in U.S. Pat. No. 5,007,908 to Rydell for"Electrosurgical Instrument Having Needle Cutting Electrode andSpot-Coag Electrode". Rydell's device includes an elongated flexibletubular member with a plurality of lumens. The distal-end of the tubularmember is provided with a bullet shaped ceramic tip covered with aconductive layer and having an opening coupled to a first one of thelumens. The conductive layer is coupled to a conductor which extendsthrough a second one of the lumens to an electrical source. A secondconductor, also coupled to the electrical source is slidable through thefirst lumen by a plunger. The two electrodes form a bipolar pair. In asecond embodiment, the conductive layer on the ceramic tip is split byan insulating gap and both halves of the tip form a bipolar pair ofelectrodes. Rydell's device does not provide any grasping capability.

Other electrocautery probes for use with an endoscope are disclosed inU.S. Pat. No. 3,920,021 to Hiltebrandt. Hiltebrandt discloses severaltypes of probes similar to Rydell's in that they have a substantiallybullet shaped tip with hemispheric or annular conductors formingelectrode pairs. Hilterbrandt also shows electrodes similar to Guay's, apair of springy arms slidable through a tube member to grasp and releasetissue. Of course, the gripping force obtainable by either Guay's orHiltebrandt's probes is severely limited because the electrodes must be"springy".

A bipolar electrocautery endoscopic scissors sold by Everest Medical isalso known in the art and generally comprises a first fixed scissorelement which is coupled to an outer tube, and a second rotating scissorelement which is coupled to a push rod. The scissor elements areinsulated from each other by use of ceramic layers glued to the faces ofthe scissors, and by an insulated pin around which the scissor elementextend. Likewise, the outer tube which is connected to a first electrodewire, and the push rod which is coupled to a second electrode wire areinsulated from each other, and the outer tube and push rod are coupledto a handle and actuator which effect movement of the push rod relativeto the outer tube. While the Everest Medical bipolar electrocauteryscissors provides the basics of a bipolar electrocautery endoscopicinstrument, it has several drawbacks. In particular, the connectionbetween the electrodes and the outer tube and push rod are by wireswhich are forced distally in between a ferrule and the push rod, andbetween an insulator on the push rod and the outer tube. This electricalconnection is undesirable, however, as when the push rod and outer tubeare rotated relative to the handle, electrical connection may not beproperly maintained, and/or the wire contacting the outer tube may workits way proximally and end up contacting an uninsulated portion of thepush rod, thereby establishing a short circuit. Moreover, because of thelocation of the outer tube electrode wire between the push rod and theouter tube, electrical arching is possible which could result in a shortcircuit between the electrodes.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a bipolarendoscopic electrocautery instrument having a tube and push rod havingsecure bipolar electrical connections to the tube and push rod.

It is also an object of the invention to provide an endoscopicelectrocautery instrument having a tube and push rod coupling a proximalactuator to a pair of distal grippers where one gripper is supplied withone pole of a bipolar cautery current through the tube and the other endgripper is supplied with the other pole of a bipolar cautery currentthrough the push rod.

It is another object of the invention to provide a handle for anendoscopic instrument having a proximal bipolar electrocauteryconnection to a tube and push rod of the endoscopic instrument, wherethe tube and push rod may be rotated relative to the handle of theinstrument without disturbing the electrocautery connection.

It is a further object of the invention to provide an endoscopicinstrument with a distally extending actuator which is operable by theindex finger of a practitioner.

Another object of the invention is to provide an endoscopic bipolarelectrocautery instrument with a proximal actuator having a forceamplifying design so that the force applied at the end effectors isgreater than the force applied at the actuator.

It is also an object of the invention to provide an endoscopic bipolarelectrocautery instrument with a proximal insulating gas seal betweenthe tube and the push rod.

It is still another object of the invention to an endoscopic bipolarelectrocautery instrument having a pre-bent push rod which is directlyconnected to an end effector.

Yet another object of the invention is to provide an endoscopic bipolarelectrocautery gripper instrument where gripping and electrocauteryprocedures are enhanced by providing gripping surfaces which areparallel when the grippers are in a position intermediate of open andclosed.

In accord with these objects which will be discussed in detail below,the endoscopic bipolar electrocautery instrument of the presentinvention includes a proximal handle having bipolar electrical contactstherein which are separately coupled to a tube and push rod which areinsulated from each other. The tube and push rod are in turnrespectively coupled to a fixed distal jaw and a rotating distal jawwhich are likewise insulated from each other. The tube is covered withan insulating shrink wrap from its flared distal end up to a proximalportion which is uncovered. The stationary jaw is provided with anintegral clevis which is mounted inside the flared distal end of thetube thereby making electrical contact with the inner surface of thetube. The clevis holds a pair of ceramic insulators between which amovable jaw is rotatably mounted on an insulated bushing and an axlepin. A proximal end of the movable jaw is coupled to the push rod by atang pin. The push rod is covered with an insulating shrink wrap from apoint just proximal of its distal connection with the movable jaw to apoint near its proximal end.

On the proximal end of the instrument, the uninsulated proximal end ofthe tube is mounted in a conductive bushing which is freely rotatablewithin a nonconductive handle. A nonconductive rotatable ferrule ismounted on a portion of the tube immediately distal of the handle.Rotation of the ferrule relative to the handle rotates the tube, pushrod, and jaws relative to the handle. The proximal end of the push rodextends proximally beyond the conductive bushing and a nonconductive gasseal is fitted between the bushing and the push rod. A non-conductiveactuating lever is hingedly attached to the handle and is coupled to thepush rod by a ball and set screw arrangement which permits the ball, andhence the push rod to rotate relative to the actuating lever. Movementof the lever moves the push rod through the tube to open and close thedistal jaws. A pair of Y-shaped electrical wiper contacts are preferablyinsert molded in the handle and respectively contact the bushing anduninsulated portion of the push rod on either sides of the gas seal. Abipolar cable is coupled to these contacts and is also preferably insertmolded in the handle.

Preferred aspects of the invention include: forming opposing jaw faceswith a distally receding angle so that teeth on the jaw faces grip moreevenly; forming the clevis of the stationary jaw with protrusions whichkeep the ceramic insulators from rotating with the movable jaw;including a finger ring on a portion of the lever so that the jaws canbe actuated by movement of a single finger; extending the lever adistance from its hinged connection with the handle to increase theforce applied at the jaws; pre-bending the distal end of the push rod inorder to reduce the friction between the push rod and the outer tube,and thereby reduce the amount of force required to actuate the movablejaw as well as the possibility of wearing through the insulation; andforming the ferrule with a distally extending notched neck so that theinstrument may be lockingly inserted into the valve body ofsuction-irrigation instrument described in previously incorporated Ser.No. 07/959,280.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a broken longitudinal cross sectional view of the inventionshowing the proximal and distal ends;

FIG. 2 is an enlarged side elevation view of the proximal end of thetube;

FIG. 3 is an enlarged longitudinal cross sectional view of the flareddistal end of the tube;

FIG. 4 is an enlarged side elevation view of the proximal end of thepush rod;

FIG. 5 is an enlarged side elevation view of the distal end of the pushrod;

FIG. 6 is an enlarged longitudinal cross section of the handle bushingand gas seal;

FIG. 7 is an enlarged side elevation view of the stationary jawincorporating a clevis;

FIG. 7a is an enlarged top view of the jaw of FIG. 7;

FIG. 7b is an enlarged end view of the jaw of FIG. 7;

FIG. 8 is an enlarged side elevation view of the movable jaw;

FIG. 8a is an enlarged bottom view of the jaw of FIG. 8;

FIG. 8b is an enlarged end view of the jaw of FIG. 8 taken along line8b--8b of FIG. 8;

FIG. 9 is an enlarged side elevation view of one of the two ceramicinsulators used to insulate the movable jaw from the clevis of thestationary jaw;

FIG. 9a is an enlarged top view of the insulator of FIG. 9;

FIG. 10 is an enlarged side elevation view of the insulating bushingused to mount the movable jaw in the clevis of the stationary jaw;

FIG. 10a is an enlarged top view of the bushing of FIG. 10;

FIG. 11 is an enlarged side elevation view of the axle pin which fitsinside the insulated bushing;

FIG. 11a is an enlarged top view of the axle pin of FIG. 11;

FIG. 12 is an enlarged side elevation view of the tang pin used tocouple the movable jaw and the push rod;

FIG. 12a is an enlarged top view of the tang pin of FIG. 12;

FIG. 13 is an enlarged transparent view of the assembled distal end ofthe instrument of the invention with the jaws in the closed position;

FIG. 13a is a view similar to FIG. 13, but of the jaws in the openposition;

FIG. 14 is a side elevation view of the lever actuator of the instrumentof the invention;

FIG. 14a is a bottom view of the lever actuator;

FIG. 14b is a cross sectional view taken along line 14b--14b in FIG.14a;

FIG. 15 is bottom view of the insulated handle of the instrument of theinvention;

FIG. 15a is a cross sectional view taken along line 15a--15a of FIG. 15;

FIG. 16 is a side elevation view of the cable assembly;

FIG. 16a is a top view of the cable assembly;

FIG. 16b is a distal end view of the cable assembly;

FIG. 17 is a top view of the ball coupling for use in the lever;

FIG. 17a is a cross sectional view taken along line 17a--17a in FIG. 17;

FIG. 18 is a side elevation view of the ferrule; and

FIG. 18a is a proximal end view of the ferrule.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIGS. 1-6, the endoscopic bipolar electrocauteryinstrument 10 of the invention is shown in longitudinal cross sectionwith a break between the proximal end 12 and the distal end 14. Startingwith the distal end 14, a stationary electrically conductive jaw 16 ismounted inside the flared end 18 (FIG. 3) of an electrically conductivetube 20. A movable electrically conductive jaw 22 is rotatably mountedin a clevis portion 24 of the stationary jaw 16 by an axle pin 26 havinga nonconductive bushing 28. A pair of ceramic insulators 30, 32 areplaced on either side of the jaw 22 in the clevis portion 24 ofstationary jaw 16 in order to electrically insulate jaw 22 from jaw 16.The movable jaw 22 is further provided with a tang 34 which ismechanically and electrically coupled by a conductive tang pin 36 to aconductive push rod 38. Push rod 38 extends axially within tube 20 tothe proximal end 12 of the instrument 10. Both the push rod 38 and thetube 20 are covered with shrink-wrap insulation 39, 21 respectivelyalong all but a portion of their length. In particular, the push rod 38is covered with insulation except for a flattened distal end 37 whichcouples to the tang 34 of the movable jaw 22, and except for theproximal end 50 (FIG. 4) which makes electrical contact with a wiperdescribed below. As seen best in FIG. 5, the distal end of the slightlyflexible push rod 38 is pre-bent slightly off-axis to better couple thepush rod 38 to the tang 34 of movable jaw 22 without undue rubbingagainst the inside of tube 20. In this manner, not only is wearing ofthe insulation 39 on the push rod reduced, but the force necessary toactuate the movable jaw 22 is likewise reduced.

The proximal end 12 of the instrument 10 includes an insulated handle 40having a circular cross section and central distal opening 42 into whichthe tube 20 and push rod 38 extend. A ferrule 41 is attached to the tube20 and partially covers the handle 40. The proximal end 44 of the tube20 (FIG. 2) is not covered with shrink-wrap insulation and ismechanically and electrically coupled to a brass bushing 46 (FIG. 6)which is rotatably mounted in the central opening 42 of handle 40.Bushing 46 is provided with a flange 46a which holds the bushing insidethe central opening 42 of the handle 40, and an annular groove 46b forreceiving and holding a rubber seal 48. Rubber seal 48 is provided withan inner extending lip 48a which engages the annular groove 46b of thebushing. A tubular portion 48b of the seal 48 extends into the proximalend of the bushing 46, and a sealing lip 48c engages the push rod 38.Rubber seal 48 provides a gas-tight seal between the push rod 38 and thetube 20 and also provides additional electrical insulation between thepush rod and the conductive bushing 46.

According to the preferred embodiment of the invention, a pair ofY-shaped electrical wiper contacts 52, 54 are insert molded in a cableassembly 56 and mounted inside the handle 40 as will be described inmore detail below. Contacts 52, 54 are coupled to a bipolar cable 58which in turn is coupled to a source of cautery current (not shown). Thehandle 40 is further provided with a rivet or axle 60 which is laterallyoffset from and perpendicular to the longitudinal axes of tube 20 andpush rod 38, and which couples the handle to a substantially J-shapedlever 62 which is mounted for rotation on the axle 60. The proximal endof lever 62 is provided with a ball coupling 64 having a diametricalbore 65 and a set screw 66 which intersects the bore 65. The proximalend of push rod 38 is inserted into the bore 65 and fastened to the ballcoupling 64 by the set screw 66. Lever 62 is also provided with a cablecover 68 through which bipolar cable 58 passes. The J-shaped lever 62extends distally from the handle, and a finger ring 70 is provided nearthe distal end of the lever 62.

Those skilled in the art will appreciate that rotation of lever 62 movesthe push rod 38 relative to the tube 20 and rotates the movable jaw 22about the axle 26. The length of lever 62 magnifies the force applied toit so that a relatively small force applied by the finger of apractitioner inserted in the finger ring 70 results in a much strongergripping force between jaws 16, 22. It will also be appreciated thatrotation of ferrule 41 rotates both the tube 20 and the jaws 16, 22about the longitudinal axis of the instrument 10. The ball coupling 64in the handle 62 allows the push rod 38 (and the ball 64) to rotaterelative to the handle. However, the Y-shaped wiper contacts 52, 54maintain a good electrical contact with the tube and the push rodregardless of the angular position of the tube and push rod, as thewiper contacts are in the handle and do not move.

Turning now to FIGS. 7 through 12a, components of the distal end of theinstrument are shown in greater detail. The stationary jaw 16 is shownin detail in FIGS. 7-7b. There it can be seen that the jaw has agenerally cylindrical stepped diameter proximal portion includingcylindrical steps 76, 78, and 80. Extending therefrom is the distal endeffector 71 having a centrally located integral clevis portion 24 and agripping surface 72. Comparing the proximal portion of the jaw 16 withthe flared distal end of the tube 20 in FIG. 3, and as shown in theenlarged assembled view of FIG. 13, it will be appreciated that thesmallest diameter proximal end 80 of jaw 16 is dimensioned to fit insidethe smaller diameter portion 18a of the distal end 18 of tube 20. Thenext larger diameter portion 78 of jaw 16 is dimensioned to fit insidethe larger diameter portion 18b of the flared distal end 18 of tube 20.The largest diameter portion 76 of the proximal end of the jaw 16 has anouter diameter substantially equal to the outer diameter of the largerdiameter portion 18b of the flared distal end 18 of tube 20. Thecentrally located clevis portion 24 of jaw 16 is a substantiallyrectangular opening which extends from the top of the jaw through thebottom of the jaw. The clevis portion 24 communicates with the interiorof tube 20 by a longitudinal bore 75 which extends from the proximal endof the clevis portion 24 through the stepped diameter portions 76, 78,80. As seen best in FIG. 7b, bore 75 extends through the bottom 74 ofthe proximal portion of the jaw, thus leaving an opening in the bottomof the jaw from the proximal end through to the distal end of the clevisopening 24. Those skilled in the art will appreciate that this bottomopening 74 accommodates the pre-bent distal end of push rod 38 as shownin FIGS. 1, 5, 13, and 13a. The clevis portion 24 of jaw 16 is alsoprovided with axle holes 86, 87 for mounting movable jaw 22 as describedin detail below. Hole 86 has a relatively larger diameter than hole 87and hole 87 has an outward flare 87a. The proximal end of clevis portion24 is provided with two steps or protrusions 82, 84 and the distal endof the clevis portion is provided with ramped edges 90, 91. A proximalfloor portion 73 of the end effector 71 extends proximally below theramped edges 90, 91. The protrusions 82, 84 and floor portion 73 holdceramic insulators 30, 32 mentioned above and described in detail below.

FIGS. 8, 8a, and 8b show details of the movable jaw 22. The movable jaw22 has a distal semi-cylindrical portion 108 with a lower grippingsurface 110, and an intermediate portion 112, and a proximal tang 34.Intermediate portion 112 is provided with an axle hole 114 for receivingceramic bushing 28 and axle pin 26 as described in detail below. Thetang 34 is split into parallel arms 118, 119 between which the distalend 37 of push rod 38 fits as described below. The parallel arms 118,119 are provided with coupling holes 116, 117 for receiving the tang pin36 as described below.

FIGS. 9 and 9a show details of the ceramic insulator 30 which take theform of elongated, shaped washers. Comparing FIGS. 7, 8, and 9, it willbe appreciated that the insulator 30 has a profile substantiallymatching the profile of the clevis portion 24 of jaw 16 andcorresponding in part to the profile of the intermediate portion 112 ofjaw 22. Insulator 30 has a central hole 92, a lower proximal notch 94, alower distal notch 96 and an upper distal ramp 98. Insulator 30 isplaced inside the clevis portion 24 of jaw 16 so that its lower proximalnotch 94 rests on top of protrusion 82; its lower distal notch 96 restson floor portion 73; its ramp 98 aligns with ramp 90; and its centralhole aligns with hole 87. An identical ceramic insulator 32 (FIGS. 1,13, and 13a) is placed inside clevis portion 24 aligning with step 84,hole 86, ramp 91 and floor 73. The two insulators 30, 32 thereby linethe inner walls of clevis 24 and prevent contact between the movable jaw22 and clevis 24. As an alternate to the elongated, shaped ceramicinsulating washers, two medical grade, high Durometer silicone washersmay be used. The silicone washers may be round or otherwise shaped asdesired and provide a good degree of insulation. In addition, thesilicone washers effectively seal against the movable jaw 22, therebyensuring that the ceramic bushing 28 around which the movable jaw 22rotates is kept entirely within the jaw 22 and the silicone washers.

FIGS. 10 and 10a show the ceramic bushing 28 around which the movablejaw 22 rotates, and FIGS. 11 and 11a show the axle pin 26 which extendsthrough the ceramic bushing. The ceramic bushing 28 has an outerdiameter 28a dimensioned to fit comfortably within the hole 114 inmovable jaw 22 and in the holes 92 of the ceramic (or silicone)insulators 30, 32, and an inner diameter 28b dimensioned to accept axlepin 26. The ceramic bushing extends across the longitudinal axis of thesurgical instrument from insulator 30 to insulator 32. The axle pin 26has a relatively wide body 26a which extends through the insulator 32and provides strength to the bushing, and slightly narrower tips 26b,26c. At least one of the tips preferably has a small counterbore thereinso that the tip may be spread in the flared hole 87a of the clevis ofjaw 16 by a riveting instrument during assembly.

FIGS. 12 and 12a show the tang pin 36. Tang pin 36 has a flat head 36aand a distal counterbore 36b which is spread in assembly to form arivet-like connection between the distal end 37 of the push rod 20 andthe hole 116 in the tang 34 of the movable gripper jaw 22.

Turning now to FIGS. 13 and 13a and with reference to FIGS. 7-12a, whenassembling the distal end 14 of the instrument 10, the two ceramicinsulators 30, 32 are inserted into the clevis opening 24 in thestationary jaw 16 as described above. The ceramic bushing 28 is insertedinto the hole 114 in movable jaw 22 and both are inserted into the spacebetween the insulators 30, 32 until the opening 28b in the bushing 28aligns with the holes 86, 87 in the jaw 16. The axle pin 26 is theninserted into hole 86 of the jaw 16 with its counterbored narrow end 26bfacing narrower diameter hole 87. The counterbored narrow end 26b isthen spread in tapered hole 87a by a riveting instrument. The distal end37 of the push rod 38 is then coupled to the tang 34 by inserting theflattened distal end 37 between arms 118, 119 until the hole 37a alignswith the holes 116, 117. Tang pin 36 is then inserted and spread with ariveting instrument.

As seen in FIG. 13, when the distal end 14 of instrument 10 isassembled, the gripping surfaces 110, 72 of jaws 22, 16 are not parallelwhen the jaws are in the closed position. Rather, these surfaces(defined by the apex of the ribs or teeth 110a, 72a, of the jaws) mateat the distal end of the jaws, and are angled away from each other inthe proximal direction as indicated by angle "A" such that the ribs orteeth 110a, 72a do not touch at their proximal end. By forming thegripping surfaces this way, when the jaws are gripping an object, abetter gripping action is achieved. In particular, the angle of thegripping surfaces are chosen such that when the jaws are gripping anobject that they are likely to encounter, the jaws assume a parallelposition which is intermediate their open and closed positions.

FIGS. 14 through 18a show components of the proximal end of theinstrument in greater detail. As mentioned above, the actuating lever 62(shown in detail in FIGS. 14, 14a, and 14b) is a substantially J-shapedmember which extends from the proximal end 12 of the instrument 10towards its distal end 14 (FIG. 1). At its proximal end, the actuatorhas a pivot bore 62a in a handle receiving space 62d which permits theactuator lever to be coupled to the insulated handle 40 as describedbelow. The proximal end of lever 62 includes a ball receiving opening62b which receives the rotating ball 64 (which is coupled to the pushrod), and a cable receiving opening 62c through which a bipolar cable 58extends. The distal end of the lever 62 has a broadened paddle portion62e which extends anywhere from between two to five inches (andpreferably at least four inches) distally. Extending from the distal endof the paddle portion 62e and at a preferred angle of approximatelyforty-five degrees is a finger ring 70. The lever is preferably a moldedplastic piece which is shaped such that the proximal end 62f of thelever is rounded and narrow and fits ergonomically in the palm of thehand of the practitioner when the hand is cupped with the thumb beingparallel to the middle finger (to actuate rotation of the device asdiscussed hereinafter), while the paddle portion 62e substantiallyparallels the longitudinal axis of the instrument such that the pointerdigit of the practitioner can slip into the finger ring 70. Becauseforce to the actuator is applied at the finger ring location, and thatlocation is removed from the pivot bore 62a rotation location, theforces applied to the push rod are amplified accordingly.

Turning to FIGS. 15 and 15a, the insulated handle 40 is seen. The handle40 is a substantially cylindrical member provided with a substantiallyrectangular lower opening 40a for receiving a cable assembly 56 (FIG.16). The handle also has a pair of arms 60a, 60b which define a slot fora tab 56a of the cable assembly. The arms include holes 40d forreceiving an actuator axle 60. The handle 40 also includes a distalopening 42 which is provided with a seat or recess 42a for receiving theflange 46a of bushing 46. A horizontal key slot 40b is located betweenthe opening 40a and seat 42a for receiving a key 56c of the cableassembly. A substantially rectangular proximal opening 40c faces andreceives a portion of the proximal end of the lever 62.

The cable assembly 56 of the invention is seen in FIGS. 16 and 16a andincludes a proximal vertical tab 56a having a hole 56b therein, a distalhorizontal key 56c, and a distal notch 56d. Two Y-shaped wipers 52 and54 which are coupled to separate wires of bipolar cable 58 which ispreferably insert molded in the cable assembly are themselves preferablyinsert molded in the cable assembly 56. The Y-shaped wipers 52, 54 arespaced apart, with wiper 52 being proximal of wiper 54. It will beappreciated that wiper 54 provides electrical contact to the tube 20(FIG. 1) and is wider and shorter than wiper 52 which provideselectrical contact to the push rod 38 (FIG. 1). According to a presentlypreferred embodiment, the wipers are constructed of a pair of resilientconductive strips which are pre-bent as seen best in FIG. 16b. Inparticular, wiper 54, which provides contact to the tube 20 is providedwith first lower bends 54a, 54b having angles of approximately 42degrees from vertical. Second intermediate bends 54c, 54d bring thewiper blades into a substantially vertical spaced apart position andupper outward bends 54e, 54f provide a smooth entry for the tube 20. Itwill be appreciated that the distance between the blades of wiper 54 issmaller than the outer diameter of the tube 20 and that the blades areresilient enough to grip against the tube 20. Wiper 54, which providescontact to the push rod 37 are provided only with upper bends 52a, 52bwhich provide a smooth entry for the push rod between the blades of thewiper 52. The cable assembly 56 is inserted into the handle 40 in amanner discussed below.

The coupling ball 64 which couples to the push rod and permits rotationof the push rod relative to the handle 40 and actuating lever 62 isshown in more detail in FIGS. 17 and 17a. The ball 64 has flattenedsurface portions 64a which permit insertion of the ball 64 into theopening 62b of the lever 62, a first bore 65 for receiving the push rod38, and a second bore 66 for receiving a set screw (not shown) whichfixes the push rod in the ball 64. A circumferential groove 64b whichruns diametrically relative to bore 65 is provided for permitting a thinscrewdriver or the like to engage the ball while the set screw is beinginserted during assembly so that the push rod will not be bent due tothe force exerted on the set screw.

A final component of the preferred instrument of the invention is aferrule 41 which is shown in detail in FIGS. 18 and 18a. The ferrule 41extends around and is used for rotation the outer tube 20. The ferrule41 has a central bore 41a through which the tube 20 extends, a tapereddistal end 41b, an intermediate groove 41c, a flared proximal portion41d with an inner circular flange 41e, and outer finger grippingprotrusions 41f. Those skilled in the art will appreciate that thecircular flange 41e provides a friction reducing interface between theferrule and the handle so that rotation of the ferrule is not impeded,while the finger gripping protrusions 41f are provided to permit thepractitioner to cause a rotation of the ferrule 41, and hence the outertube 20, grippers 16, 22, etc.

Comparing FIGS. 15-18a and FIG. 1, those skilled in the art willappreciate that after the distal end 14 of the instrument 10 isassembled as described above, the ferrule 41 is mounted on the tube 20by press fitting. The proximal ends of tube 20 and push rod 38 are theninserted into the distal opening 42 of the handle 40. Bushing 46 ispress fit to tube 20 so that flange 46a rests inside the recessed seat42a of opening 42 and the seal 48 is attached to the proximal end of thebushing as described above. The cable assembly 56 is inserted into thebottom opening 40a of the handle 40 so that its horizontal key entersslot 40b and its lower distal notch 56d enters the flared proximalportion of the ferrule 41. The vertical tab 56a of the cable assembly isthen inserted between arms 60a and 60b until the hole 56b aligns withthe holes in the arms 60a, 60b. As the cable assembly is inserted intothe handle, the widened ends 52a, 52b of wiper 52 spread the wiper 52around the push rod to embrace it and the widened ends 54e, 54f of thewiper 54 spread the wiper 54 around the tube to embrace it. The ballcoupling 64 is inserted into the ball receiving opening 62b in lever 62and rotated so that it can receive the proximal end of the push rod 38.Wires 58 from cable assembly 56 are threaded through the opening 62c inthe lever 62 and the lever is aligned with the handle so that arms 60a,60b holding vertical tab 56a enter the space 62d in the lever 62. Theproximal end of the push rod 38 is directed through bore 65 of ball 64.An axle pin 60 is then inserted through holes 62a, 56b in the lever 62and the handle 56. Cable cover 68 is then snapped over the opening 62c.Upon setting of the end effectors in their closed position, the setscrew (not shown) screwed into the set screw bore 66 in the ball 64, anda cover (not shown) is snapped over the opening 62b.

The operation of the endoscopic bipolar electrocautery instrument withgrasping end effectors is as follows. The distal end 14 of theinstrument 10 is inserted into a trocar tube in a conventional manner.The practitioner grasps the proximal end 12 of the instrument 10 byinserting an index finger through finger ring 70 and, if desired, bygripping ferrule 41 with a thumb and a middle finger. Cautery currentmay be controlled through a conventional foot switch (not shown).Movement of the index finger of the practitioner opens and closes thejaws as described above. In addition, rotation of the ferrule rotatesthe jaws about the longitudinal axis of the instrument. As mentionedabove, the instrument of the invention is designed so that it can beused advantageously with an endoscopic suction-irrigation instrumentdescribed in Ser. No. 07/959,280. Thus, the instrument 10 of theinvention may be inserted into the fluid chamber of thesuction-irrigation instrument until the instrument 10 is locked in placeby the locking pin engaging the groove 41c in ferrule 41. The instrument10 conveniently fits with the lever 62 alongside the pistol shapedhandle of the suction-irrigation instrument so that the lever can beoperated by the index finger of the practitioner while the practitionerholds the pistol-grip handle of the suction-irrigation instrument.

There have been described and illustrated herein the preferredembodiment of an endoscopic bipolar electrocautery instrument withgrasping end effectors. While particular embodiments of the inventionhave been described, it is not intended that the invention be limitedthereto, as it is intended that the invention be as broad in scope asthe art will allow and that the specification be read likewise. Thus,while particular end effectors have been disclosed, it will beappreciated that other types of end effectors could be utilized with theinstrument. Also, while particular devices have been shown to insulateone jaw from the other, it will be recognized that other types ofinsulating devices could be used with similar results obtained.Moreover, while particular configurations have been disclosed inreference to the bushing, seal, and wiper contacts, it will beappreciated that other configurations could be used as well.Furthermore, while a J-shaped actuator having a finger ring has beendescribed as being advantageous, it will be understood that differenttypes of actuators can achieve a similar function. It will therefore beappreciated by those skilled in the art that yet other modificationscould be made to the provided invention without deviating from itsspirit and scope as so claimed.

We claim:
 1. A bipolar endoscopic surgical instrument comprising:a) ahollow electrically conductive tube having a proximal end and a distalend, said tube being covered with an outer first electrically insulatingwrap except for an electrical contact receiving non-insulated outerproximal portion of said tube; b) an electrically conductive rod havinga proximal end and a distal end, said rod being covered with a secondelectrically insulating wrap except for an electrical contact receivingnon-insulated outer proximal portion of said rod and an outer distalportion of said rod, said rod extending through said tube; c) anelectrically non-conductive handle coupled to said proximal end of saidtube; d) a first electrically conductive end effector mechanically andelectrically coupled to said tube; e) a second electrically conductiveend effector electrically and mechanically coupled to said distal end ofsaid rod and pivoting relative to said tube; f) first insulating meansfor electrically insulating said second electrically conductive endeffector from said first electrically conductive end effector; g)actuating means mechanically coupled to said handle means and saidproximal end of said rod for imparting reciprocal motion to said rodrelative to said tube which is translated to pivoting motion of saidsecond end effector; and h) second annular insulating means forelectrically insulating said electrical contact receiving non-insulatedouter proximal portion of said rod from said tube during said reciprocalmotion, said second annular insulating means being non-gaseous, saidsecond annular insulating means remaining substantially stationaryrelative to said hollow electrically conductive tube during saidreciprocal motion, and said second annular insulating means extendinginto an annular space between said rod and said tube.
 2. An endoscopicinstrument according to claim 1, wherein: said second insulating meansis a rubber sealing gasket.
 3. An endoscopic instrument according toclaim 1, further comprising:i) an electrically conductive clevismechanically and electrically coupled between said distal end of saidtube and said first electrically conductive end effector, wherein,saidfirst insulating means electrically insulates said second electricallyconductive end effector from said clevis.